British and American prisoners held at Mauthausen in 1945

Lt. Jack Taylor of the OSS (USN) was captured during the Dupont mission and arrived at Mauthausen in December 1944 - he states that two US and one British PoW were confirmed to have been executed there by gunshot.

I can't find anything on American deaths at this camp.

SOE agents are known to have been executed there in September 1944 but I presume that Taylor is talking about executions that occurred while he was held there.

One option for the British POW is Corporal Warndorfer of the Intelligence Corps who was captured in Slovakia and later executed at Mauthausen following torture. (information from elsewhere in this forum)

https://www.findagrave.com/memorial/12906430/august-jacques-warndorfer

 

Taylor also mentions there being another American serviceman in the camp at the time of liberation.

Sergeant Louis Biagioni, ASN 12185480, OSS SI agent captured in northern Italy in summer 1944 and held for some months by Gestapo in Italy, then transferred to Mauthausen. On December 26th, he was taken to Linz, tried, condemned to death and returned to Mauthausen. He split wood in the garage while awaiting his execution.

Lionel Romney, Negro fireman, U.S. Merchant Marine, 'S.S. Makis' sunk off Pantelleria 17 June 1940, captured by Italians and interned eventually in Mauthausen. He did lumberjack work in the forest for which he received extra food.

Sergeant Biagioni, Lionel Rommney, and Lt Taylor were liberated in early May 1945

 

He also mentions there being two British officers in the camp:

One of them must be Captain John Starr (John Ashford Renshaw Starr - born 06.08.1908) of the SOE who was captured in France in 1943 and eventually sent to Mauthausen. He spoke fluent French and posed as a Frenchman so he could be evacuated from Mauthausen when the surviving Frenchmen were released in late April 1945

This is the one I am having a problem with: "1st Lt. Toni Speare, RAF fighter pilot, downed in France, spring 1944, and captured in civilian clothes while trying to escape through the French underground. He was suffering from boils and temporary loss of sight and voice."

Obviously the rank is incorrect for an RAF officer, but I have tried everything I can think of including alternate surname spellings to search POW records via RAFCommands plus checking the London Gazette and TNA without finding a firm possibility for this person