The three other booksellers are still believed to be in mainland China.
Lui Por was one of five men associated with Causeway Bay Books to go missing and then resurface in police custody in China, sparking fears that Chinese authorities had abducted them.
Mr Lee, a British passport holder, told China's Phoenix Television last week that he had not been kidnapped by Chinese authorities, as many suspected, but had snuck into China illegally and that he would renounce his British citizenship.
Gui, a prolific author of often-salacious and thinly sourced books that cater to Chinese tourists in Hong Kong, re-appeared in China in January saying in a televised confession that he had voluntarily turned himself into authorities over a fatal 2004 traffic accident. Thousands of people demonstrated in Hong Kong to demand their return.
Thomson ReutersA closed sign is seen outside the Causeway Bay Book in Hong Kong, ChinaHONG KONG (Reuters) - One of five missing Hong Kong booksellers specializing in gossipy publications about Chinese leaders and detained in China returned home on Friday, Hong Kong police said.
Cheung Chi Ping met with police yesterday and asked them to drop inquiries into his disappearance, according to a statement posted on the government's website.
"Police continue to follow through with the other two missing person cases with the Interpol Guangdong Liaison Office of Guangdong Provincial Public Security Department for further details", Hong Kong police said.
Chinese state media reported last week that Lui, Cheung and another Hong Kong resident Lam Wing Kee would be released on bail in "a few days'".
The Hong Kong police said on Wednesday that Lui and two other booksellers had been freed on bail while under criminal investigation in mainland China, citing information from the authorities in Guangdong province, which borders Hong Kong.
Hong Kong police confirmed in a statement that Lui, who went missing in October past year, had returned to Hong Kong Friday morning, according to broadcaster RTHK.
A fourth bookseller, Lee Bo, remains in the mainland, purportedly to assist into an official investigation into fellow bookseller Gui Minhai.
Lui was shown in footage released by Phoenix Television earlier this week "confessing" his ties to banned book sales in China.
Lee, who appeared in an "exclusive" interview with Phoenix TV on Monday, said he wished to give up his British rights. However, authorities have not been able to confirm when Lam will return to Hong Kong.