A Labour MP's ­judgment has been questioned over his backing for a Labour-supporting businessman's restaurant.

An East Kilbride curry house run by Amerjit Singh was raided by immigration officers earlier this month – the second time it has happened to his businesses in five years.

Local MP Michael McCann nominated Asha's restaurant for a prestigious award last year, despite illegal workers being found at another of Singh's eateries four years previously.

Singh used to run the Village Tandoori Indian restaurant in East Kilbride. However, an immigration raid in 2008 uncovered seven illegal workers on the premises.

Singh, who is a Labour Party member, was not punished. However, according to a local newspaper report, he received a verbal warning from immigration officials.

McCann then nominated Singh's new Asha's restaurant – based at 4 Glebe Street – for the Tiffin Cup in 2012.

The competition is held annually to find the best South Asian restaurant in the UK, with the winner being decided by MPs and celebrities.

McCann said at the time: "I have been dining and buying takeaway Indian food from Amiy Singh's restaurants in East Kilbride for years and the standard of his food is excellent."

Singh was quoted as saying: "We are delighted that Michael thought of us when he made the nomination and we hope to be given the opportunity to impress the judges at the final stages at the House of Commons."

McCann's website also carries articles relating to the Tiffin Cup competition.

However, immigration officers raided Asha's this month, as well as another restaurant in the town.

A Government source said an Indian man was allegedly working at Asha's illegally and had been arrested and detained.

The source added that the business had been served with civil penalty notices, which could lead to a £10,000 fine.

According to Registers of Scotland records, the commercial block in which Asha's is based is owned by Kean Properties, a company that has Labour-supporting businessman James Kean as one of two directors.

In 2009, Kean Properties made a planning application to change the use of 4 Glebe Street from a shop unit to a restaurant and hot food takeaway.

Although the development was deemed "contrary" to the Development Plan, South Lanarkshire Council's planning committee granted the application.

Singh told the Sunday Herald the latest raid was based on a "mix-up".

Asked whether he was a Labour member, he said: "I am."

McCann was elected as the MP for East Kilbride, Strathaven and Lesmahagow in 2010.

John Wilson, an SNP MSP for Central Scotland, said: "Mr McCann as a public representative should think carefully about his support for individuals such as Mr Singh."

Adam Scarcliffe, from the Home Office Immigration Enforcement Team, said: "Illegal working fuels illegal immigration to the UK and that is why we are carrying out operations like these.

"If you are a business, you must carry out the correct checks on your staff or you could end up with a heavy fine.

"We are happy to work with businesses to let them know what checks need to be made on staff, but those who break the law should know that they will face heavy fines."

McCann declined to comment.