CELTIC fans have been warned they face a life ban for touting AC Milan tickets.

The club put out that message today and also told their fans not to travel to Italy if they don't have an official ticket.

On the ebay website today, bids are being invited for Celtic tickets for Tuesday's Champions League first leg.

The club are actively policing such sites and say anyone caught selling tickets for either tie will be banned from Parkhead. And, if they do trace such tickets, the buyers won't get in, either.

Celtic are aware supporters are desperate to see Tuesday's game and the return in the San Siro on March 20.

But Tuesday's tie is already sold out, and Celtic have been told they will receive only 4850 tickets for the vital return game in Milan.

That was the original official allocation and has been distributed to fans travelling on official Celtic trips and to fans on the Euro away game register.

This leaves around 5000 supporters, who have booked independently to go to Milan, desperately searching for tickets.

And, with the San Siro capacity slashed to 40,000, their chances of picking up tickets in Milan are greatly reduced.

Celtic are conscious of the serious security implications if fans get into the wrong section of the ground and are doing all in their power to prevent this happening.

They are also mindful of the fact they are responsible for the behaviour of every fan who attends Tuesday's game, which is why they have taken details of every fan who has purchased a ticket.

If these tickets are subsequently sold, it undermines this strict security system, and the club are doing all in their power to avoid this happening.

But they know they need the co-operation of supporters and issued a warning to dissuade anyone considering selling their ticket, even though there is huge profit to be made.

A spokesperson said: "Celtic is against such actions and finds the exploitation of fellow Celtic supporters completely unacceptable.

"We would stress the club views such activity very seriously and will have no hesitation about taking strong action in relation to those people who are found to be involved in this activity.

"Celtic will adopt a strict zero tolerance policy on this issue. Any person found to be selling tickets in this way will be banned indefinitely from Celtic Park."

A major security operation will be mounted to ensure Tuesday's game will proceed without any problems.

And a deputation from the club are also being sent to Milan. With heightened security surrounding all games in Italy following the death of a police officer at a game two weeks ago, the prospect of thousands of Celtic fans going without tickets is giving cause for concern.

Although proud of the reputation of supporters at home and abroad, president of the Affiliation of Celtic Supporters' Clubs, Peter Rafferty, has urged the club to lobby Milan and Uefa for more tickets.

He said: "They will still go - huge amounts have paid their money."