'I don't like to think of myself as a grave-­robber," says Charles Ardai, co-founder (with Max Phillips) of crime fiction imprint Hard Case Crime.

"More a preserver of antiquities. Indiana Jones is a grave-robber, but he doesn't call himself that."

I don't bring up the word, but it's clear that some people might think of him that way. After all, Hard Case is on the verge of resurrecting eight pseudonymous novels by the late Michael Crichton - author of runaway bestsellers including Jurassic Park and The Andromeda Strain - that were originally published during the late 1960s and early 1970s under the name John Lange.

Ardai, 43, has never been one for sitting still. He was chief executive of dotcom-boom success story Juno - an internet service provider which is now a subsidiary of United Online - and has spent the past decade or so establishing a highly distinctive line of books that recall the classic days of pulp fiction. On top of this, he is consulting producer on SyFy TV show Haven, and writes his own award-winning noir fiction under the pseudonym Richard Aleas. He has also found time for a personal life, and is a father to a young daughter and husband of best-selling fantasy author Naomi Novik.

In person, Ardai is relaxed, unassuming and warmly engaging. He's forgotten more about fiction - and especially pulp fiction - than most people will ever know. When he talks about the subject he loves, he lights up with a genuine, utterly infectious passion. I first met him when he was in the process of establishing Hard Case in 2005, and his immense enthusiasm for the writers he works with only seems to have grown in the interim years. He isn't ground down by hard work; he is energised by it.

It's easy to see, from the way he charms the staff during our breakfast meeting at New York's Upper West Side bistro, Sugar And Plumm, how Ardai has persuaded literary estates - and many still-living authors with extensive back catalogues - to hand over unfinished and forgotten works, along with brand new novels. The Hard Case brand extends to well over 100 titles with impressive names peppering the line-up. Nearly every book reflects Ardai's personal taste, plus a few oddities that he considers too important to be abandoned because their cultural interest or significance trumps his personal feeling. It is part of his duty as a "citizen of the arts".

Hard Case has published new and rediscovered work by authors including Donald E Westlake, Ed McBain and Mickey Spillane. The imprint's most recent triumph was the publication of James M Cain's previously unpublished final novel, The Cocktail Waitress.

The pseudonymous Crichtons are yet another coup. They will be the first time Crichton is publicly acknowledged as Lange. Ardai had already re-published two of the novels while Crichton was still alive, but never even hinted at the truth behind the man's identity.

All the same, the Lange pseudonym seems to have been an open secret - other authors claim to have been aware of it for some time. Also in the loop was best-selling horror writer Stephen King, who, after writing his first novel for Hard Case in 2005, enthused to Ardai: "Tell [Crichton] Steve says to write a new John Lange book. Do it. Go for it."

Encouraged by King's enthusiasm, Ardai got in touch with Crichton through his agent and made the pitch. King's recommendation, along with Hard Case's unique style and design, persuaded Crichton this was the ideal way to give Lange a new lease of life.

The Lange books were originally published during Crichton's years at medical school. Ardai admits there are varying accounts as to why Crichton adopted a pseudonym for these early novels. The first is that Crichton "didn't want the professors at the medical school to know that he was spending time on anything other than cutting up cadavers". It seems a reasonable concern, but the second story is equally plausible: "He didn't want the people in Harvard to know he was writing racy, sexy potboilers, because they would diminish the prestige of the institution."

Whatever the truth, Crichton still wanted the Lange novels to remain pseudonymous - not because he was ashamed of them, or regarded them as juvenilia, but they were different enough from his later work that he didn't want any confusion as to whether they were new Crichton books or not.

Ardai could republish the books as long as he didn't publicly mention Crichton. This was an agreement he took seriously. When Crichton died in 2008, a journalist called, asking Ardai for a quote. It was the first that Ardai heard about Crichton's death, and it took him by surprise. "I said, 'What do you mean, death of Michael Crichton? And why would I have words about it? He's not one of our authors. We have an author named John Lange, but I don't see why you're asking me about Michael Crichton.' So I ducked the question."

Crichton and Ardai had been in the midst of a discussion about which of the books to publish next - there were eight in total - when the author died. Ardai took a step back to let the family sort everything out. Two new Crichton novels - one already written, the other completed by Richard Preston - were released by the estate, and after suitable time had passed, Ardai raised the possibility of completing the Lange reissue. Crichton's estate decided that if they were going to continue, they needed to go all-in. They asked that all eight books be published simultaneously. Their second condition was that Crichton's name finally appear on the covers. As Ardai says, "They wanted to give him credit for this extraordinary job he did."

The new Hard Case editions are striking. Crichton himself loved the hand-painted art for 2006's re-issue of Grave Descend and the later release of Zero Cool. Like all Hard Case books, they look like collector's items, to be bought as much for their design as for the stories inside. I have to wonder if this is why Ardai doesn't seem to be doing e-books (a tactic also employed for Stephen King's new novel Joyland, which came out this summer).

But the truth, as with any good mystery, is more complex. Crichton himself was - perhaps surprisingly, given the techno-centricity of his thrillers - not enamoured of e-books, and didn't want to give e-rights to anyone while he was alive. But Jane Friedman - who had worked with Crichton for more than 30 years - did manage to obtain the rights for e-editions of the Lange novels. This doesn't really bother Ardai; he knows that the Hard Case editions offer something that Friedman's Open Road ones don't: "[Readers who buy e-books] will miss out on the beautiful covers by Greg Manchess and Glen Orbik."

This is important to Ardai. While Hard Case books do have e-editions - in fact, Stephen King's Joyland is print only at the request of the author - Ardai is far more concerned with print editions. And so, he believes, are the people who buy Hard Case. "Many of [our readers] … like the artefact we've created as an art object. Some of them might not even read it - they might just stick it in mylar." But those who do wrap their books in protective plastic will be missing out on some brilliant hardboiled classics, carefully curated by a curious, excitable and passionate citizen of the arts.

As our breakfast draws to a close, we discuss the ethics of posthumous publishing - via tales of Kafka and Nabokov - and Ardai sums up why it is important to preserve these books, even if they are sometimes lacking the polish an author might have given them had they lived.

He says: "If I could find a tape recording of my grandmother - who has been dead these last 10 years - I would be delighted to hear it, even if it were just her saying, 'Pick up some milk on the way home'. Because it's a voice I treasure. And that's the same for writers who become friends of their readers, or at least … are regarded as a friendly voice, perhaps even part of the family."