Manchester United's attempts to sign Robert Lewandowski blocked by Borussia Dortmund

The Poland international is among the most coveted strikers in Europe

Robert Lewandowski has been told he will not be allowed to leave Borussia Dortmund for either Bayern Munich or Manchester United this summer.

Both clubs had been preparing deals in excess of £20m to sign the 24-year-old forward, whose goals fired Dortmund to the Champions League final at Wembley.

Lewandowski has spoken of his desire to quit the Bundesliga runners-up and was in line to double his current £2 million-a-year deal.

However officials at Borussia Dortmund told the Polish striker he would have to see out the final 12 months of his contract at the club. They also insisted no deal had been made before the Champions League final to allow Lewandowski to move to Munich.

“Such a promise to Robert has never existed,” said Dortmund's chief executive Aki Watzke. “We have said everything that had to be said.

”I can understand he is disappointed. If I was him I'd also be disappointed to hear about FC Bayern not making an offer for him.

“What I expect from him now is to show the strength in character he has shown over the past years and cope with the situation on a professional level. I am confident that he will do so. 2014, when his contract runs out, he is welcome to join Munich.

”I can only call off the wish I know about. Why should I bother about other clubs when all we know about is that he only wants to join Bayern.“

Doubt over Wayne Rooney's future at Old Trafford has heightened Manchester United's interest in a player who scored 10 goals in European competition last season and has scored 66 goals for Dortmund in the last two campaigns.

Bayern had been thought to be preparing a bid of £20m, with Lewandowski having only one year left on his contract. They have yet to firm up that initial interest.