Williams is a lifelong fan of the club

The pop star grew up in Stoke-on-Trent and has supported the club since he was a child.

"Although I can't be at the Vale often, my investment is just to say that my heart is still there and I'm a huge supporter," Williams said.

Port Vale chairman Bill Bratt said he welcomed the investment, the size of which has not been disclosed.

He confirmed that Williams has bought the remaining available shares in the club.

There was £260,000 worth of shares remaining at the beginning of February.

'Secure the future'

Mr Bratt said he was "extremely pleased and excited" about Williams' stake, which "clearly shows that he cares about Port Vale FC and its future".

"It's now up to the board and all at Port Vale FC to ensure his investment is used wisely in helping to secure the future at the club," said Mr Bratt.

Three years ago Williams turned down a chance to invest in the club, which had been suffering financial problems at the time.

"I'm really excited about what we may be able to do with the club in the future," he said in a statement on Monday.

Vale manager Martin Foyle added: "I've always known Robbie's heart is in the Vale - I'm delighted, but not surprised by what he has done."

Warnock wants more focus on football and promotion

The ban comes in after midfielder Alan Quinn's arrest following an alleged incident at a pub last week.

Warnock told the club website: "I'm not going to fine Alan but we can't go into pubs because we can't let anything detract from what we're trying to do."

"This is not an alcohol ban however, they can get drunk at home after the game if they want to."

Warnock is worried that his players may be distracted from their main aim of securing promotion to the Premiership.

And he added: "Even if a player is drinking orange juice he can still get into trouble in a pub if certain people are there."