The growing row between property tycoon Vincent Tchenguiz and Superwoman fund manager Nicola Horlick escalated today as her only listed fund complained to the City watchdog that Tchenguiz had lied about how much backing he has for his bid to sack the board.

At the same time Tchenguiz denied claims he faces a margin call soon on the £40 million he borrowed from bust Icelandic bank Kaupthing to buy his 28.8% stake in Bramdean Alternatives.

Today Bramdean Alternatives, whose hedge fund and private equity-type investments are made by Horlick, sent a legal letter to Tchenguiz family trust Elsina demanding that he show signed statements from shareholders who back him.

The letter from Simmons & Simmons says Tchenguiz told Bramdean Alternatives chairman Brian Larcombe he had "written undertakings of support" from over 50% of the shareholders.

But Elsina's letter requisitioning a shareholder meeting, and the related Stock Exchange announcement, spoke only of a "significant proportion" of shareholders backing it.

The lawyers also refer to press coverage of the battle where Tchenguiz has been regularly described as having anything from 50% to 65% support.

They point out that anyone "making a statement, promise or forecast which he knows to be misleading, false or deceptive" has committed market abuse.

The letter adds that if the statements by Elsina and KBC Peel Hunt as to the level of support are untrue they would amount to an offence under Section 397 of the Financial Services Act."

Meanwhile, banking sources said Tchenguiz has a £40 million credit facility with Kaupthing, now in administration, that falls due for repayment on 9 July.

It is believed this was partly used to finance his stake in Bramdean Alternatives. But a Tchenguiz spokesman said "it is completely untrue we face a margin call on this debt," and that "we have renegotiated all our outstanding facilities with Kaupthing for up to three years."

When Horlick launched her first publicly quoted fund 20 months ago Tchenguiz backed her, buying his 28.8% stake at the flotation price of 100p a share. That cost him just over £26 million.

Until last week's announcement of a potential takeover bid the Bramdean Alternatives share price had slumped.

It hit a 40p low before recovering to 55p today.