A London lawyer has told how Asda security guards who wrongly suspected him of shoplifting “imprisoned” him at a bus stop — despite him not setting foot in the store.

Bryan McCutcheon alleges that the guards grabbed him outside the Harrow branch, rifled through his rucksack and called him a “liar”.

He is now suing the supermarket giant for £15,000.

In a writ lodged at the High Court, Mr McCutcheon said two security guards approached him as he waited for a bus outside the store and accused him of shoplifting before attempting to grab his rucksack to retrieve the “stolen items”.

When he challenged them, he claims they called him a “liar” and said he had been caught on CCTV. Mr McCutcheon said the drama escalated when his bus approached and he asked to be let go.

In court papers, he claimed he was “imprisoned” at the bus stop and held for 45 minutes before a third shop worker went to check the footage and realised the mistake.

Mr McCutcheon said: “I obviously felt very, very embarrassed, and more shock than anything to be honest.

“To be singled out in the street with all those people around, when I was just going home, was just awful. It was rush hour.”

His partner, recruitment consultant Ena Vieira, was also upset and urged him to take action.

Mr McCutcheon, who completed the Bar Professional Training course at BPP in Holborn, said: “I decided to take legal action because I have had little to no cooperation from Asda in resolving why it happened.

“I have had no apology and they have said nothing in their defence. It’s appalling.”

Mr McCutcheon, a case assessor for an independent legal auditor, was on his way to collect his 22-month-old son Daniel from his mother-in-law in Harrow on May 4 when he was allegedly accosted by staff at the Northolt Road branch.

He said: “Because of this, I was late for my son and Ena arrived to collect him before I did. When I told her what happened she couldn’t believe it.” Mr McCutcheon, who moved to London from Northern Ireland in 2006, is using his legal background to mount the claim himself.

The writ states that Mr McCutcheon’s reputation was seriously damaged by the accusations and loss of liberty, and that he has suffered “considerable hurt, distress and embarrassment”.

It adds that the events have also been damaging to his career.

An Asda spokeswoman today said: “We’re aware of the claim and it’s under investigation.”