Police in Cambodia say that an outspoken Spanish environmental activist was deported after the expiration of his visa.

The Monday deportation of Alex Gonzalez-Davidson came after the anti-dam campaigner had refused an order from Prime Minister Hun Sen to leave the country.

Gonzalez-Davidson was a co-founder of a non-governmental group called Mother Nature, which opposes the construction of a controversial hydropower dam in southwestern Cambodia's Koh Kong province.

On Monday Prime Minister Hun Sen ordered him to leave the country, following the Friday expiration of his visa.

The Spaniard had vowed to remain in Cambodia and was arrested Monday, then deported on an evening flight, said Interior Ministry spokesman Gen. Khieu Sopheak.