IBM is suing an online retailer for trademark infringement, deceptive trade practices, false advertising and unfair competition.

Big Blue said that it first became aware of the problem when a customer in Ohio bought a ThinkPad laptop battery from Shentech.

An overheating problem caused the laptop to catch fire, and an examination by IBM revealed that the battery was a fake.

IBM then ordered 12 other ThinkPad batteries from the website which it also claims were fake.

The firm filed suit against the web retailer in the US District Court for the Northern District of Ohio on 20 November.

IBM is asking the court to force Shentech to hand over all the fakes to be destroyed, surrender any profits made from their sales and award treble damages or $1m "per counterfeit mark per type of item sold".

An allegation posted on the Reseller Ratings website makes the same claim about an IBM laptop battery.

"I ordered what I thought was a genuine Lenovo replacement battery. It turned out to be counterfeit," online poster 'Esquire07' alleged on the site.

"It had all the right stickers that said it was made by IBM except for the serial number. My computer immediately detected that it was not genuine."

A number of buyers on the same ratings site have also made allegations that other big name brand products sold by Shentech were fake.

"Bought a Toshiba laptop battery that died in 3 mos. It seemed suspicious when it didn't fit quite the same. Counterfeit. Beware!" wrote 'Painlus'.

"Merchant sold me a counterfeit Sony 4gb PRO Duo memory card," said 'ocwvrdr'.

"Sold me a counterfeit SanDisk Extreme II card," said 'Wombat77'.

Shentech was contacted for comment but has yet to respond.