Mbesuma, one of the hottest properties in African football, scored 35 goals for South African champions Kaizer Chiefs last season as his team stormed to a second successive title.

Real Madrid, Chelsea and Aston Villa were other clubs linked to the 21-year-old, with Bolton close to signing him - but boss Sam Allardyce wanted a few days to look at the player.

His agent, Mike Makab, told Portsmouth's official website, that the deal was subject to Mbesuma getting a work permit.

"There were no hard feelings with Bolton and the manager was great - but they just wanted to look at Collins for a three or four days," said Makab.

"There was enough interest from other clubs for Collins however and what with his record and the DVDs that they had there was enough of his talent on show to simply do a deal.

"I think Pompey's gain will be a few other clubs' loss."

The striker is currently on a visa and returns to Zambia on Wednesday, although the club hope he will be back with them early next week.

Pompey will then apply for the work permit and if that is granted the player will be applying for permission for his family to come to England.