MIDDLESBROUGH are preparing the ground for a bitter legal battle with Liverpool as the Premier League drag their feet over the Christian Ziege saga.

Boro, who claim the German wing-back was the subject of an illegal approach before he completed his controversial £5.5m move to Merseyside early this season, have now been waiting five months for a verdict on their complaint.

Ziege exercised a get-out clause in his contract, permitting him to speak to any club offering £5m or more for his signature, but was forced to take Boro to court to win his release from the Riverside after they attempted to block the deal.

Boro complained to the Premier League, alleging Ziege had been "tapped'' by a third party - believed to be former Germany coach Berti Vogts - on Liverpool's behalf.

Liverpool boss Gerard Houllier described Boro's allegations as "laughable''.

Boro chairman Steve Gibson responded by accusing Liverpool and Ziege of "lies and deceit'' and threatened to take the matter back to court if the Premier League dismiss the claims.

Boro are understood to be seeking a further £2.5m from Liverpool as compensation for the loss of Ziege, who had joined them from AC Milan for £4m in August 1999.

The Teessiders' calculation is based on the belief that Chelsea and Spanish giants Valencia were willing to pay £8m for Ziege, who confirmed he had other options before finally signing for Liverpool and linking up with fellow German internationals Dietmar Hamann and Markus Babbel.

Two months ago, the Premier League said: "We're in contact with both Middlesbrough and Liverpool and we'll be reaching a conclusion shortly.''

But yesterday a spokesman told Northern Echo Sport: "The matter hasn't come to a conclusion yet. We're still talking to both parties and we're awaiting further submissions to get the full facts.

"It's something we're seeking to resolve, but there is no timescale.''

Gibson has shown his tenacity before by taking legal action and enlisting the late George Carman QC in an ill-fated attempt four years ago to win back the three points Boro were deducted by the Premier League for failing to fulfil a fixture.

The self-made haulage tycoon, recently listed as Britain's joint-288th wealthiest person with a £108m fortune, is again gearing up for a fight to the finish.

Gibson said Liverpool "inflicted maximum damage'' on Boro by making their move for Ziege on the eve of the season.

And he added: "Liverpool know and Ziege knows exactly what went on and we wish to expose that through the correct channels so that the matter can be resolved to the satisfaction of the Premier League rule book.

"The rules have clearly been broken. I would hope the severity of any damages would be a warning to all clubs.

"It's an on-going situation and we haven't closed the option of taking the matter outside football.''

To add to the intrigue, Liverpool chief executive Rick Parry held a similar post with the Premier League when Boro were docked the points which ultimately cost them top-flight status.

l Boro have dismissed suggestions that they could become embroiled in football's dual-passports probe.

Newcastle's Peruvian winger Nolberto Solano, whose work permit expired, has seen the validity of his Greek passport called into question.

Boro's Australia duo Mark Schwarzer and Paul Okon, along with Cameroon international Joseph-Desire Job and Argentinian Carlos Marinelli, also hold European Community passports.

But a Boro spokesman said: "There are no problems with our players at all.

"Mark's father and mother are German, Paul's father is German and his mother is Italian, Joseph was born in France and Carlos has Italian grandparents.''

l Boro scouts are expected to be out in force this weekend, with Paris St. Germain striker Christian likely to come under scrutiny.

The Brazilian has already been watched by Boro and head coach Terry Venables confirmed: "We'll be having another look at him.''

Boro have also checked on Alaves' £6m-rated striker Javi Moreno