It was like a scene from Hamish MacBeth. Police launched a full-scale drugs raid on a Highland home - but discovered only the 79-year-old owner's tomato plants.

Uniformed officers burst into Lulu Matheson's house in the village of Shieldaig, Wester Ross, kept her son Gus in his bedroom for two hours, handcuffed her grandson Stephen, and turned the house upside down.

The high-profile afternoon raid involved three squad cars, seven officers and sniffer dogs. They told the family they were looking for cannabis, but after searching for several hours had to concede the green plants visible in the window from the roadside were tomatoes.

The plants, of which police requested a sample for analysis, were bearing fruit.

The swoop follows on a number of recent drugs busts across the Highlands in which rented houses have been found converted to cannabis "factories".

But Mrs Matheson, a widow who has lived in the house for 53 years, was flabbergasted when the police poured into her home.

She said: "I got a terrible fright and I couldn't understand what they were doing here because I knew we had nothing more than tomatoes in the window. I don't know what the neighbours must be thinking."

Gus Matheson, 47, a former diver, said: "I was standing looking out the window at the pier when I saw two cop cars pull up beside the house with five officers getting out and I wondered what on earth was going on. I opened the door and they more or less barged past saying that I was growing cannabis on the windowsills."

He added: "It was a terrible carry-on. The police didn't even apologise."

Mr Matheson now intends to make a formal complaint.

A spokesman for Northern Constabulary said last night: "Recently we have had a lot of high-profile raids on properties where cannabis has been grown, as there have been across Scotland. These have been conducted on an intelligence-led basis acting on information. But on this occasion no controlled substances were found."

He denied it was a heavy-handed operation.