Prime Minister David Cameron is cutting short an African trade tour to fly back to Britain to take control of an inquiry into the phone-hacking scandal that has led to the resignation of the country's top policeman, media reported on Monday.

The Guardian said Cameron had halved the tour's length to two days from four, and will only visit South Africa and Nigeria. Plans to visit Sudan and Rwanda have been cancelled, it said.

The phone hacking scandal led to the arrest Sunday of Rebekah Brooks, a former editor of the News of the World, and the shock resignation of Stephenson.

In a statement issued by his office late Sunday, Cameron described Stephenson's departure as "a very sad occasion for him," adding: "I wish him well for the future."

Brooks resigned as chief executive of Rupert Murdoch's News International newspaper division on Friday, although she denies wrongdoing.

Cameron is friends with Brooks, and has also come under fire for his decision to employ her successor as editor, Andy Coulson, as his media chief until January. Coulson was also arrested earlier this month over hacking.

Stephenson quit after pressure over his links with a former deputy editor of the News of the World, Neil Wallis, who was arrested last week, but he took a sideswipe at Cameron over his ties to Coulson.

The prime minister will fly home on Tuesday to allow him to finalise the arrangements for Lord Justice Leveson's inquiry into the media, the newspaper said.

The Financial Times said the prime minister was returning to the Britain to fend off criticism that he was out of the country in the midst of the scandal.

It cited a source close to the prime minister as saying that the Africa trip had been shortened to enable him to focus on events closer to home.

Cameron argued that a free trade area could increase gross domestic product across the continent by an estimated $62 billion a year -- $20 million more than the world gives sub-Saharan Africa in aid.

African leaders agreed in South Africa last month to launch negotiations on creating a free trade zone that would include 26 countries with a combined economy estimated at $875 billion (597 billion euros).

"There are quite a few pressing things going on," the source told the FT.

Agencies