Chelsea and Manchester United have both attempted to sign Hamburg striker Heung-min Son, according to the South Korean's agent.

The 20-year-old only recently signed a new contract extension after progressing through the youth academy and forcing his way into the first team plans of Hamburg manager Thorsten Fink.

Heung-min Son
Heung-min Son signed for Hamburg when he was just 16-years-old. [Reuters]

Son first joined the German side when he was 16 after making the bold decision to leave South Korea in order to pursue a career in Europe. He has since gone on to make more than 60 appearances for the Bundesliga club and has played an important role in the first team this season.

He has scored nine league goals which appears to have caught the attention of Manchester United and Chelsea, both of whom are said to have approached Hamburg over a possible deal for the striker.

Son's agent, Thies Bliemeister, confirmed the interest of the Premier League duo, whilst also revealing that Italian giants Internazionale had sent representatives to watch the striker in action.

"Inter Milan's emissaries saw a couple of his matches, but so far I have not had any contact with the Italian club's officials," he told Interlive, as reported by Sky Sports.

"A transfer in the next summer? He has signed a new contract with Hamburg SV extending it for one year, but there have been many offers for him as from Manchester United and Chelsea."

It is unclear whether these offers came during the January transfer window or whether they were attempting to broker a deal that would see him move in the summer.

His contract now expires in the summer of 2014 so if Hamburg believe he is interested in leaving then they may be forced to cash in on the striker at the end of the season rather than risk him running down his contract.

The forward has made 16 appearances for South Korea, scoring one goal, and was involved in a friendly earlier this month as they were beaten 4-0 by Croatia.