Joan Collins says late sister Jackie "wasn't just a star" but "an entire galaxy".

Joan Collins

Joan Collins

The legendary actress has paid a touching tribute to author Jackie Collins - who tragically died from breast cancer on September 19 - on her official website.

Joan, 82, recalled the moment Jackie revealed her stage four breast cancer news to her - seven years after being diagnosed.

She wrote: "My voice was so choked with tears I could hardly speak. She explained that since we spent so much time in Europe while she was in LA, she knew I would be worried but there would be nothing I could do.

"That was typical of my sister. She always put other people, particularly family, ahead of herself.

"After we hung up we called two of her daughters, Tiffany and Rory, and they verified that they had been taking their mother for treatments for over five years."

The 'Dynasty' star also told of her deep sadness at the loss of Jackie, who was 77 at the time of her death.

She explained: "I don't think I will ever recover from the sadness of losing my beautiful baby sister. Someone once said, 'The reality is that you don't 'get over' the loss of a loved one, you learn to live with it.' I think Jackie would have liked us to do more than that. As she requested, I will not mourn her death, but rather celebrate her life."