An inquiry is to be launched in Birmingham into the "black arts" practice of supermarket chains buying huge land banks to kill off competition.

The retail giants face a Birmingham City Council investigation amid claims they are stockpiling land in an attempt to dominate trade and squeeze out the small shopkeeper.

Deputy council leader Paul Tilsley, who has ordered a wide-ranging inquiry into land ownerships of Tesco, Sainsbury's and Asda, said the big-three sometimes used "black arts" to buy sites they had little intention of developing.

The purpose was to make sure competitors could not acquire the land and build superstores themselves, Coun Tilsley (Lib Dem Sheldon) claimed.

Singling out Tesco, he said Britain's largest supermarket group was intent on expanding so quickly in south Birmingham that it would soon be able to "knock out the competition".

But he was accused of double standards by campaigners against superstores, who pointed out that the council is set to pocket millions of pounds by selling two large sites to Tesco.

A residents' associations meeting in Hodge Hill last night urged council leaders to freeze a plan to sell 1.7 acres of playing fields to Tesco. The land, off Brockhurst Road, has been designated for a 65,000 square feet superstore.

Last month, the council sold land adjoining the Swan Shopping Centre in Sheldon to Tesco for the development of a superstore.

Roger Gordon, a spokesman for the Hodge Hill and Ward End Residents' Associations, said: "How can the council say it is worried about domination by the supermarket chains and is investigating this, when it then sells land to Tesco? Talk about double standards, it just doesn't make sense."

The council inquiry reflects national concern about the relentless rise of the super-store within the UK's £9 billion grocery sector. The Office of Fair Trading will shortly announce whether it is to refer the sector to the Competition Commission.

Earlier this week, J Sains-bury announced its intention to spend £100 million over the next two years on buying and developing new sites.

Coun Tilsley said: "The council deals with planning applications as a one-off and is not looking at the bigger picture. We need to consider the whole strategy of how some communities are effectively over-shopped while others probably don't have enough shops."

Accusations of double standards were dismissed by Ken Hardeman, Birmingham City Council's cabinet member for regeneration.

Coun Hardeman (Con Brandwood) said: "There is nothing wrong with selling land. Yes, we make a lot of money but it is reinvested into services for the city and to help us achieve our aspirations for Birmingham."

Tesco was unavailable for comment last night.