LAGOS, Oct 23 (Reuters) - Shares in Nigerian oil firm Oando Plc have been frozen at 5.99 naira until further notice, the stock exchange said on Monday after the regulator ordered a forensic audit into the company.
The Securities and Exchange Commission (SEC) had suspended trading in the stock for 48 hours last week, saying it was investigating complaints about insider trading and discrepancies in its ownership structure.
The regulator said it would freeze the price until further notice. A regulatory source said the freeze aimed to avoid volatile trading pending the outcome of the audit.
By 1114 GMT, no trades at the firm's fixed share price had been reported.
Oando has said it was aware the regulator had received petitions and said the allegations were "unsubstantiated, misleading and defamatory".
A company source has said the petitions centred around the ownership of some Oando shares bought through an investment vehicle at the time the company bought the Nigerian unit of U.S. firm ConocoPhillips for $1.65 billion in 2014.
Oanda could not be reached for comment on Monday.
In July, Oando shares fell close to a one-month low after the regulator said it was investigating the firm's shareholding structure following the ConocoPhillips unit acquisition.
The SEC has said a team of auditors, lawyers, stockbrokers and share registrars would conduct the forensic audit to ensure independence.
Trading in Oando's shares have also been suspended in Johannesburg, where it has a secondary listing.
Oando has gained 27 percent this year after a sharp fall last year. It last traded at 5.99 naira. (Editing by Edmund Blair)