A Romanian recluse lay dead in his Sydney flat for up to seven weeks before his decomposed body was found on his bedroom floor beside buckets he probably had used to vomit in.

Police could only locate one relative, a brother living in New Zealand, who said he wanted no further contact from them.

The acting state coroner could not ascertain the cause of Bodo Cazimir's death. Credit:Kate Geraghty

In Glebe Coroners Court on Wednesday, acting state coroner Teresa O'Sullivan found Bodo Cazimir, 64, died in his Drummoyne flat between May 19 and July 6, 2015, but could not ascertain the cause or manner of death.

Mr Cazimir, who was believed to have been a professor of music, had been diagnosed with a large tumour in his bladder months earlier but had refused any treatment, the inquest was told.