LONDON - Digs at the London Olympic site have unearthed evidence of Iron Age and Roman settlements, authorities said on Wednesday.

Pottery and a Roman coin have been found on the site of the planned Aquatics Centre in Stratford, east London.

They were buried behind a wooden river wall that may have been built and used by the Romans.

The coin, which has been dated to 330-335 AD, shows two soldiers and their standards on one side, and emperor Constantine II and Caesar on the other.

The 150-million pound Zaha Hadid-designed centre has been radically overhauled recently, with a large pedestrian bridge having been incorporated into the roof structure.

Uncertainty remains over its final cost, while only one contractor is believed to be interested in taking on the project after two dropped out.

But the Olympic Delivery Authority (ODA), responsible for creating the 2012 Games infrastructure, said the archaeological finds would not delay the building programme.

The items will go on show at the Museum of London as part of its collection and record of the site's dig.

London's Iron-Age dwellers would have lived on a small area of dry land in a valley of lakes, rivers and marshes, and would have fished in the River Lea, the ODA said.

The Aquatics Centre will be beside the river, which is currently being widened by eight metres as part of a programme to restore the ancient waterways of the Lower Lea Valley.

Archaeologists are currently dating the woodwork and trying to establish how the finds link to evidence of Roman activity in the Hackney Wick area, which would have overlooked the Lea Valley.

ODA Chief Executive David Higgins said: "It is a story of change and transformation dating back centuries."

He added: "The archaeological work has been long planned in conjunction with our programme and will not cause any delays."