Oil-rich Brunei is abuzz with rumours that its wealthy ruler Sultan Hassanal Bolkiah's second wife, a former Malaysian television journalist, is pregnant, a report said.

The Kosmo Malay-language tabloid published a front-page photograph of Azrinaz Mazhar Hakim, 26, in loose clothing that did not hide a noticeable midriff bulge.

The Brunei Information Department released the picture of Azrinaz wearing a pink outfit and a pink head scarf taken on Tuesday at a ceremony to celebrate the birthday of Prophet Muhammad.

Kosmo said that the main topic of conversation in Brunei ever since had been speculation that Azrinaz, who married Sultan Hassanal Bolkiah last August, was now about five months pregnant.

The sultan remains married to first wife Anak Saleha, whom he wed in 1967. In 2003 he divorced former flight attendant Mariam Abdul Aziz after more than 20 years together.

His latest marriage came almost a year after his son and heir Crown Prince Al-Muhtadee Billah Bolkiah, 30, wed half-Swiss commoner Sarah Salleh, 17, in a glitzy ceremony.

Much excitement

Azrinaz spent several years as a broadcast journalist and later as a newscaster with private station TV3 before resigning weeks before her marriage.

Their union caused much excitement in Brunei and Malaysia, which share a long religious and cultural heritage.

Brunei opted out of the Malaysian federation in the 1960s, enabling it to keep its oil wealth and sustain a cradle-to-grave welfare system for its 350,000 people. Royal families on both sides remain closely linked.

Before the emergence of technology billionaires such as Bill Gates, the sultan of Brunei was once rated the world's richest man, although in Brunei there is no clear distinction between state and royal family wealth.