Klien and Karthikeyan on Spyker's list

Team boss Colin Kolles told Reuters on Tuesday that Karthikeyan, who raced for him at Jordan in 2005 and is now the second Williams test driver, was on his list of possible options.

Another was Austrian Christian Klien, currently the Honda test driver after three seasons with Red Bull and their predecessors Jaguar.

Klien has driven most recently, taking part in Friday practice for Honda at the British Grand Prix last week after Briton Jenson Button suffered back pains, and visited the Spyker factory on Monday.

"For the moment, no other driver is signed," said Kolles.

"Obviously, Narain is one of the options... I think it's a good option and we are just in the process of evaluating this," he added. "Williams is informed about this possibility, yes."

Markus Winkelhock, already under contract to Spyker as a test driver and in possession of the necessary superlicence, may however be drafted in first for what would be a home race at the Nurburgring in Germany next week.

"We are looking into it... if we do Markus a favour if he's driving at Nurburgring," said Kolles. "Especially for the reason that I think he didn't do too much mileage in the car this year."

Dutch driver Giedo van der Garde, one of Spyker's other testers, does not yet have a superlicence.

The team said earlier on Tuesday they had dropped Albers with immediate effect due to non-payment by one of his main sponsors and a decision on the 28-year-old's replacement would be taken in due course.

Kolles said the move was essential for the Dutch-owned team's finances and accepted there could be a backlash in the Netherlands.

"We have to go through this period and to do the best for the team," he said. "The nationalities are not important at the moment. We have to take the best options."

The team principal said Albers's replacement need not necessarily be a driver bringing the most money with him immediately but could also be one whose performances on the track would attract further sponsorship.

He also did not rule out Albers driving for the team again one day.

"You should never say never. Formula One is a very quick business," he said. "Things could change very quickly but for the moment I can say this is the situation and we are looking at other options."

He said German rookie Adrian Sutil, the team's second driver, was in no danger of losing his place.