Staff at an animal sanctuary are mourning the death of a second white lion in less than three weeks.

Lioness Joy died a short time after one of her adult cubs.

She was found on Friday to have died suddenly in her sleep, the Big Cat Sanctuary at Smarden announced.

A post mortem examination found the 15-year old mother had a large tumour in her spleen.

A spokesman for the sanctuary said: "Having shown no signs of being unwell, this was a particularly shocking discovery and left us with no time to prepare ourselves to say goodbye.

"We have been comforted by the fact that last thing the night before, Joy had been eating well and taking her treats as usual and so cannot have been feeling unwell for very long.

"She was a good age for any lion to reach, but she will be deeply missed."

Joy would have turned 16 next February.

She arrived at the sanctuary near Headcorn with her sister Sophia in May 2012 and with male Themba, they founded its lion pride and watched their cubs grow up.

The spokesman said: "Together Joy and Sophia were an amazing force to be reckoned with. Fierce protectors of the pride but also gentle and tender mothers. "

Mama Joy, or Joy Joy as she was known by the keepers, was known for her round face and round ears. She was often described as having a teddy bear face.

The centre says she was the quiet and unassuming member of her family but as a result was often people’s favourite.

The sanctuary had announced on November 23 that one of Joy and Thembas's offspring, nine-year old male Ngozi, had died after a short illness.

He had to be put to sleep after suffering kidney failure.

Ngozi, who had three sisters, was also a favourite among visitors.

The Big Cat Sanctuary is a centre for welfare, breeding, education and conservation for all kinds of large felines.

The 32-acre compound and its animals can be briefly seen when travelling by train from Headcorn towards Ashford.

The white lion is not an albino but a rare colour mutation of the usual sandy-coloured type and its fur varies from blond to near-white.