Police are investigating a complaint from a fan who witnessed Didier Drogba throwing a coin into the crowd during Chelsea's Carling Cup defeat by Burnley on Wednesday night. The Metropolitan Police refused to disclose any further details, but Drogba's actions were condemned by all sections of the game and the prospect of a suspension looms.

Drogba threw the coin into the away section at Stamford Bridge, although it is not thought that any spectators were injured or even that anyone was hit. The Ivory Coast forward will be hoping that the fact that he reacted in retaliation to an object being thrown from the crowd and that he apologised immediately after the match will be in his favour. However, it seemed last night that he will be lucky to escape punishment as police and the FA launched separate investigations.

Police officers were in talks with the governing body and said that they were “receiving full co-operation from Chelsea”. But it emerged that one spectator has been in touch with police to lodge a complaint about Drogba's behaviour. A Metropolitan Police spokesman said: “We have received a complaint from a member of the public who was in the crowd.”

Drogba will have to wait to discover if he is to be charged with any offence and it is likely to be some days before the Metropolitan Police decide whether there is enough evidence for an arrest. Until then, Drogba will have to endure the criticism that rained down on him from all sides yesterday.

The 30-year-old had started celebrating after putting Chelsea ahead in the 27th minute of the fourth-round tie when the coin was thrown. Having made a one-fingered gesture to Burnley supporters, he then picked up the coin and threw it back.

“I tried to celebrate the goal and I received some things at me,” Drogba said in a statement on the Chelsea website. “The big mistake I did was to throw it back so if someone was hurt I just want to apologise for it. It was an incident in the heat of the moment. It was just a mistake and nothing more.”

Andy Burnham, the Secretary of State for Culture, Media and Sport, whose Leigh constituency in Lancashire is close to Burnley, condemned Drogba's action as unacceptable. He said: “Obviously a coin was thrown from the crowd, it would appear, and then thrown back. I gather Didier Drogba has apologised, which is welcome, but you just don't want to see incidents like this at all in football and it's really unacceptable on every level.”

Jamie Carragher, the Liverpool defender, was given a three-match ban after being sent off for throwing a coin back into the crowd during an FA Cup tie against Arsenal at Highbury in 2002 and Gordon Taylor, the chief executive of the Professional Footballers' Association, said that Drogba could face a similar punishment.

“It tainted a very exciting cup-tie and a great win for Burnley,” Taylor said. “He has apologised and that should be a factor in mitigation. Nonetheless, there could well be action against him. It is very unfortunate. The lad's been out injured and most people could sympathise with his reaction. But, nevertheless, it is part of the job of a professional footballer to do your best to remain calm.”

However, Taylor also pointed out that Drogba had reacted to a coin thrown from the crowd and called on the FA to examine CCTV footage to identify the culprit as part of its investigation. “It is a worry about the coin throwing,” he said. “We don't want that to become a path to be followed. No doubt Burnley will need to be spoken to with regards to their supporters and the throwing of coins. You cannot ignore the fact that a coin was thrown at a group of players.”

Burnley issued a statement in which they vowed to co-operate with all investigations into the incident. “Burnley Football Club is proud of the 6,100 supporters who made the trip to Stamford Bridge and offered magnificent vocal backing,” the club said. “However, the club does not condone any misbehaviour from supporters and we will gladly co-operate with any inquiry into the incident, either from the FA or Chelsea Football Club.”