The Poland international opened the scoring at Euro 2012 courtesy of his header against Greece a week ago and he entered the tournament on the back of another stellar season for Dortmund.
He was named the Bundesliga's player of the year after helping Dortmund to retain their title, but he has been linked with a summer departure.
Poland coach Franciszek Smuda had claimed prior to the 1-1 draw with Greece that Lewandowski was on his way to Manchester United, comments which drew an angry response from Dortmund.
Real Madrid coach Jose Mourinho has also been mooted as an admirer of the 23-year-old, but Dortmund are determined not to sell the striker, who is under contract for a further two years.
Lewandowski is unruffled by the speculation and believes a joke made by his agent may have led to some of the rumours concerning his future.
"My agent has been in demand," Lewandowski told kicker-Sportmagazin.
"They asked him if he had a meeting with Mourinho because people have seen Mourinho in Warsaw.
"My agent then tried to make a joke, saying that Mourinho would sign me if I scored four times during Euro 2012.
"I do not care what my agent is doing. I am under contract with Borussia Dortmund."