The agent of Borussia Dortmund striker Robert Lewandowski has confirmed the interest of Manchester United.

Lewandowski's agent Maik Barthel has confirmed that his client has snubbed Dortmund's offer of a new contract whilst also revealing United's interest.

"I can confirm that the (new contract) offer of Borussia Dortmund is insufficient," Maik Barthel told Bild.

"I am also able to confirm an interest of Manchester United in the services of Robert Lewandowski."