The Interior Ministry official said on Saturday, the money was paid on Tuesday, a day after the death of Ibrahim al-Rayis in a shootout at a Riyadh petrol station, but gave no details about the informant.
Al-Rayis was on a list of the 26 most wanted armed suspects published last week after the 9 November suicide bombing of a residential compound in Riyadh which killed 18 people.
Tuesday's payment was the first awarded since the Saudi government promised rewards a week ago of up to $1.9 million for information which leads to arrests of militants or which foil any future attacks by suspected al-Qaida members.
The official said al-Rayis, whose picture was published alongside the 25 other suspects in all Saudi media, was spotted by someone who recognised his face and told authorities.
"The information was real, accurate and specific and guided
the security forces to the wanted person," he said. "We gave him one million riyals ($270,000) the next day".
"We are asking all people, Saudis and non-Saudis, to help if they recognise one of the militants," he added.
The official also repeated a government appeal to the suspects to surrender and promised they would be treated "in a good way according to Islamic law".