The British man who survived being poisoned with the Novichok nerve agent on Tuesday told broadcaster ITV he found the deadly substance that killed his girlfriend in a perfume bottle.

Rowley told ITV News that he may have had the bottle in his home for several days before giving it to his partner Dawn Sturgess.

She became ill within 15 minutes and died eight days later. Rowley was also exposed but survived after hospitalization.

"I do have a memory of her spraying it on her wrists and rubbing them together," Rowley said in his first interview since being discharged from hospital on Friday. "I guess that's how she applied it and came ill."

"I guess how I got in contact with it is when I put the spray part to the bottle ... I ended tipping some on my hands, but I washed it off under the tap," he added.

He says the substance was oily and did not smell like perfume.

Rowley said that within 15 minutes of applying the substance, Sturgess complained of a headache.

"She asked me if I had any headache tablets. In that time she said she felt peculiar and needed to lie down in the bath. I went into the bathroom and found her in the bath, fully clothed, in a very ill state," Rowley said.

Police believe the Novichok was from the same batch used in the March attack on ex-Russian spy Sergei Skripal and his daughter.

British officials blame the attack on the Russian government.