Until the late 1990s, she was on an estimated £20,000 salary as a lowly worker at IRISC, an insurance broker that polices coal compensation claims for the Department of Trade and Industry.

Last year she earned £260,000 in salary plus bonus for a 20-hour week as the head of claims at Vendside, a claims- handling company wholly owned by the Union of Democratic Mineworkers which has earned multimillion-pound profits from settling claims.

In addition to a penchant for luxury cars, designer handbags and a day as a guest in the Royal Enclosure at Royal Ascot less than two weeks ago, Miss Walker has also been active in the property market.

Miss Walker, 41, and her boyfriend, Duncan Gillespie, sold their Sheffield house for £175,000 in December 2002, three months after spending £460,000 on a new home.

Earlier this year Mr Gillespie placed an internet advertisement offering to pay up to £500,000 for a one-acre plot of land with planning permission for a four-bedroom house.

Miss Walker is also the sole owner of a company called Indiclaim Ltd, which was known as Walker and Co (Claims Services) Ltd before changing its name in March 2004. Mr Gillespie is Indiclaim’s company secretary.

For reasons disputed by the parties involved, Indiclaim has received payments from two solicitors’ firms that earned millions by settling UDM claims handed to them by Vendside.

The UDM insisted yesterday that Indiclaim had no connection with the union, Vendside, Neil Greatrex, the UDM’s president, Mick Stevens, the UDM’s vice-president, or any individual UDM claimants.

A union spokesman said that Indiclaim, which had more than £500,000 in its bank account on the date of its most recent annual return, merely provided training in claims- handling skills and risk assessment to law firms pursuing industrial injury cases.

“There is no link, financial or otherwise, between Indiclaim and any individual (UDM) claimant. There is no fee levied against any particular case. The only connection (between the UDM/Vendside and Indiclaim) is her (Miss Walker’s) name in that what she does at one doesn’t impact on the other,” he said.

However, Beresfords, a Doncaster solicitors that made payments to Walker and Co, gave information to The Times which made clear the close ties between Miss Walker’s company and a senior UDM official. Beresfords’ managing director, Mark Farrell, said that his firm had made payments to Miss Walker’s company at the request of Mr Stevens, who in addition to being vice- president of the national UDM is the general secretary of the union’s Nottinghamshire section, which owns Vendside.

Mr Farrell said that until late 2001, Beresfords, which was receiving claims from the UDM, had been making payments to Vendside to cover its vetting, marketing and administrative work on compensation cases.

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