Did Jack the Ripper confess in Australia?

In March 1892 it was reported that a man in Melbourne Gaol had confessed to being Jack the Ripper. Frederick Bailey Deeming was awaiting trial for the murder of his wife, Emily Mather. He married her in Rainhill, England on 22 September 1891, before leaving for Australia. After his arrest the bodies of his first wife, and children, were found in Rainhill.

He allegedly said that he killed the last two of the women in Whitechapel and committed the Rainhill murders. Presumably the two Whitechapel murders were Alice Mc Kenzie on 17 July 1889 and Frances Coles on 13 February 1891. This statement attracted global attention with further allegations following. Deeming used multiple aliases in a criminal career that spanned from South Africa back to England.  

Deeming himself denied the confession, and there was a suspicion that it was part of an insanity defence for his forthcoming murder trial. Or a ploy to be extradited back to England. Although Deeming’s death mask in the Black Museum was later said to belong to Jack the Ripper, there is no evidence that the police suspected him. Nor did they agree that Coles and McKenzie were killed by the same man who murdered five women in Whitechapel in 1888. Deeming’s whereabouts in that year have never been ascertained. He was in Hull prison when Frances Coles was murdered.