A Kansas state senator likened Planned Parenthood to a Nazi concentration camp after learning that a donation had been made to the organisation in his name. The Republican lawmaker made the comparison in a letter penned to Planned Parenthood last week, local media reported.

Senator Steve Fitzgerald wrote to the health organisation, saying it was with "great dismay" that he received their letter informing him of the donation. "This is as bad, or worse, as having one's name associated with Dachau," he said, adding: "Shame on anyone that would attempt to blacken my name in this manner."

Dachau was the first concentration camp established by the Nazis, according to the United States Holocaust Memorial Museum.

Fiztgerald stood by his remarks and the letter he sent to Planned Parenthood in an interview with the Kansas City Star. "It was either send them that or ignore it," he said. "I figured, I don't want my name associated as a donation to Planned Parenthood, in my name, to go on undenounced by me."

According to the Kansas City Star, the lawmaker called the donation, which was made by constituent Ali Weinel, and letter informing him about the donation "harassment" and "political theater". He added: "I think the Nazis ought to be incensed by the comparison."

Weinel told the newspaper she made the donation in Fitzgerald's name after becoming frustrated with his response to an email detailing her concerns about abortion legislation he had sponsored. "I didn't go into this out of spite," she said. "I just was so angry and knew that the only way I could be less angry was if I made a difference. So that's what I did."

Fitzgerald's response to the donation reportedly prompted more donations to be made in his name. Cecile Richards, the president of Planned Parenthood Federation of American, called his remarks disturbing.

"He should be ashamed," Richards said. "It's this kind of inflammatory language that condones the type of behaviour we see sometimes outside of women's health centres ... It's really disturbing to me that this kind of rhetoric and language is considered acceptable."

For his part, Fitzgerald maintained that the organisation was worse than the Nazis. "What I'm saying is, they're both exterminating innocent human life," he argued.