Zimbabwean Vice-President Joice Mujuru has been accused of trying to sell 3.5 tonnes of gold in defiance of international sanctions.
Ms Mujuru was appointed five years ago by President Robert Mugabe as the country's first female vice-president.
The deal reportedly involved selling Congolese gold in Europe.
There has been no comment from Ms Mujuru.
The BBC reports that she is one of about 200 Zimbabweans on whom the EU has imposed sanctions, accusing them of human rights abuses.
A company with offices in Europe, Firstar, says Ms Mujuru's daughter, Nyasha del Campo, offered to sell more than 3.5 tonnes of gold from the Democratic Republic of Congo.
Ms del Campo declined to comment and says she is consulting her lawyers.
Firstar says it withdrew from the deal when it realised who she was.
The BBC has been unable to contact Ms Mujuru. She and her husband, Solomon, a former head of the national army, are among the wealthiest and most powerful people in Zimbabwe, with extensive mining interests.