It was a legal dispute which spawned a curious footballing grudge and yet in the final episode of the Carlos Tevez affair there was a mood of solidarity as West Ham lurched towards oblivion and Sheffield United helped to keep them alive.

The London club was in financial crisis as their two-man delegation of chief executive Scott Duxbury and finance director Nick Igoe flew to Brussels to negotiate an out-of-court settlement with then Blades chairman Kevin McCabe.

It was March 2009, almost two years after they admitted to the Premier League they were guilty of signing Tevez on an illegal 'third-party' contract.

Carlos Tevez (left) and Javier Mascherano arrived at West Ham on the final day of the transfer window in September 2006 - a share of their economic rights remained with other companies

Tevez would go on to score the crucial goal away to Manchester United that kept West Ham up

On that same afternoon, Sheffield United drew with Wigan and were relegated

McCabe pursued the case through the courts to prove this wrong had denied Sheffield United the right to a place in the Premier League and with it tens of millions of pounds.

By the time his battle was won, however, West Ham's Icelandic owner Bjorgolfur Gudmundsson had been ruined by the global banking crisis and the Hammers were in turmoil.

'If we had gone before the arbitration panel to set the level of compensation it would have been a fee to be paid within 14 days,' revealed McCabe, and his account sheds new light on an old saga as the two clubs prepared to meet on Saturday in the Premier League.

'That would have created absolute chaos and potentially the demise of West Ham, and we had no desire to see a club of such standing in peril.

'West Ham are a proper football club, similar to Sheffield United in many ways with working-class roots, loyal supporters and rich history.'

Kevin McCabe (left), then the Sheffield United chairman, believed his club had been wronged by West Ham's signing of Tevez and pursued the case through the courts; Scott Duxbury (right) was West Ham's chief executive at the time of the controversy in 2007

Tevez's agent Kia Joorabchian pictured in 2007. Companies connected with him owned a share of the economic rights of Tevez and Mascherano, breaking Premier League rules

Tevez and Javier Mascherano were signed from Corinthians, in Brazil, in August 2006, but a share of their economic rights remained with companies connected to his agent, Kia Joorabchian.

This only came to light, however, when Mascherano joined Liverpool five months later.

The Premier League to set up an independent commission. West Ham pleaded guilty and were hit with a record fine of £5.5million. They did not appeal.

Crucially, no points were deducted and Tevez was allowed to play on. It remains unclear when - or even if - the unlawful contract was terminated.

They seemed destined to go down anyway. A defeat against Tottenham two days after they were charged left them 10 points adrift of safety with the worst goal difference in the league and only nine games to play.

Tevez inspired West Ham to a great escape from relegation, scoring here against Bolton

Tevez celebrates after scoring for West Ham against Tottenham at Upton Park in 2007

West Ham chairman Eggert Magnusson presents Tevez with the club's player of the year award

Then they started winning. And they won seven of the last nine games, and all of the last four, culminating in victory at Manchester United on the final day when Tevez scored the only goal.

Sheffield United needed only a draw to stay up but lost at home to Wigan in their last game and crashed back into the Championship after only one season.

McCabe set off in search of justice. He lost his initial appeal but was encouraged when the panel said they would 'in all probability' have 'deducted points from West Ham' but were powerless to change the penalty.

The next step was an independent arbitration tribunal set up by the FA and this did find in Sheffield United's favour in September 2008.

Chairman of the tribunal Lord Griffiths said there was 'no doubt West Ham would have secured three fewer points... if Carlos Tevez had not been playing.'

West Ham were still in the Premier League and banked £36.8m in broadcasting rights alone as they finished 10th in 2007/08.

But their owners had been engulfed by the financial crash - Gudmundsson was declared bankrupt in 2009 owing nearly £600m - and the club was haemorrhaging millions through a reckless business plan with lucrative deals including ill-judged signings such as Kieron Dyer and Freddie Ljungberg.

West Ham chairman Bjorgolfur Gudmundsson suffered heavily in the Icelandic banking crash, and had the club not struck the right compensation deal it could have spelled doom

McCabe was well aware of the problems. Not only were his real estate company Scarborough Group tied up with another Icelandic bank but one of his senior directors was a big West Ham fan and the company hired a corporate box at Upton Park.

Duxbury, now chief executive at Watford, and Igoe struck a deal with McCabe reported at the time to be worth around £15m with an additional £5m if the London club was sold within a year, which it was.

The key for West Ham was that this figure would be paid in instalments over four years. The deal was signed at the Connaught House Hotel in Mayfair and both sides toasted the end of an ordeal with beers in a nearby pub.

'We had developed a good relationship with Scott and Nick and were able to achieve a sensible financial solution and protect the future of West Ham,' said McCabe.

Sheffield United spent a dozen years exiled from the Premier League - six of them in the third tier - and the resentment over Tevez festered among some players, staff members and fans.

When the clubs met at Upton Park in the League Cup in 2014, and the Blades caused an upset by winning on penalties, the two sets of supporters spent much of the night baiting each other.

The theme can be expected to continue with Hammers fans planning to taunt the visitors by wearing Tevez masks on Saturday.

West Ham fans wear Tevez masks to mock Sheffield United during a League Cup game in 2014

United had the last laugh that night by winning the second-round tie on penalties

McCabe did eventually lead his club back to the top flight this year although he returned in the midst of another legal fight; one that went against him last month when a High Court judge ordered him to sell his remaining 50 per cent stake to co-owner Prince Abdullah.

He is no longer at the helm as Sheffield United travel to face West Ham as equals for the first since November 2006, when they were the opposition for the first game of the Icelandic era at Upton Park.

New chairman Eggert Magnusson promised a bright and exciting future and performed a jig in the stands to celebrate the winner scored by Hayden Mullins, who was preferred to Mascherano in midfield.

As for Tevez, he was substituted after 66 minutes and replaced by 40-year-old Teddy Sheringham.

He reacted to this ignominy by storming down the tunnel, jumping into his car and driving straight home before the game ended. A storm was already brewing.