A businesswoman was involved in a £6.6 million fake Danish Government bearer bonds deal at the time she vanished, a court has heard.

Lynda Spence was introduced to Colin Coats, one of the men who is now on trial accused of her murder, former colleague Tony Kelly told the High Court in Glasgow yesterday.

Coats, 42, is on trial with Philip Wade, 42, Paul Smith, 47, and David Parker, 38, for abducting, torturing and murdering Miss Spence, 27. They are accused of holding her hostage for up to a fortnight and assaulting her in an apparent bid to extract financial information from her. They deny the charges.

Mr Kelly, 56, who worked as a financial adviser for Miss Spence's company, Fraser Property Management, told jurors Coats was involved with her in the bond deal, which contained plans to build on land next to Stansted Airport.

A police officer involved in the case, Detective Constable Alex McEwan, said Coats told him Miss Spence owed thousands of pounds, including £100,000 to well-known Glasgow criminals.

Referring to the Stansted Airport deal, Mr Kelly was asked by solicitor-general Lesley Thomson, QC, prosecuting: "What did she tell you about that?"

Mr Kelly replied: "I don't know where the truth is. She had a blue folder about a deal at Stansted Airport. Land that had belonged to a famous individual.

"It was through a man called Uncle Ben who I never met.

"They were buying this land and selling off part of it to other developers and the Danish Government were involved because of the eco-friendly buildings that would be on the site."

Mr Kelly said he tried to get two contacts of his – Carlos Ortago and Juan Carrera – to authenticate the bearer bonds, but that fell through.

The jury was told that it was agreed the bonds would be authenticated in Raleigh, North Carolina, in March 2011. On the trip was Mr Kelly, Coats's sister Margaret Coats, her husband, Miss Spence and her girlfriend, who Mr Kelly only knew as Amelia, the court heard.

Mr Kelly said: "I think Margaret and her husband were not financially aware and wanted me to listen to what these people said."

Mr Kelly discovered the businessmen they were meeting were not there to authenticate the bonds, but to discuss an investment of £6.6m, the court heard.

Mr Kelly, now unemployed, was asked if Coats was still involved in this and replied: "He was hoping for a return on it."

He said it was later confirmed after Miss Spence was reported missing by her parents on May 13, 2011, that the bonds were fakes.

Mr Kelly told Miss Thomson he met Miss Spence in October 2009 through a friend and began working for her in 2010.

He described her business style as "absolute chaos" and added: "Her time-keeping was abysmal," but admitted that she talked a good game.

Mr Kelly said the last time he saw her in person was the day before she went missing on April 14, 2011.

Mr Kelly said she texted him at 9.16pm saying: "I'm driving to Londonx."

Earlier, DC McEwan said Coats told him Miss Spence owed thousands of pounds, including £100,000 to Glasgow criminals. She also owed £175,000 to members of the Chinese community and £100,000 to John Glen, who is a witness in the trial.

The court was also played a taped police interview with murder accused Parker, whose flat it is alleged Miss Spence was held in. In the tape, Parker said the last time he saw Miss Spence she was alive. He said: "I was trying to get her to tell the guys the truth so that it would be all over and finished with."

He said he never witnessed any assaults on Miss Spence and added: "I don't know how they muffled her, but she didn't make much noise."

At one point Parker is told by detectives they have information that Miss Spence's kneecaps were broken by a golf club.

The trial continues.