Eight more bodies were recovered Saturday from the ferry that sank off South Korea last month, officials said, amid concern that some of the missing may never be found.

Seventeen days after the 6,825-tonne Sewol capsized and sank, 236 people have been confirmed dead with 66 still unaccounted for, a government anti-disaster headquarters said in a press statement.

"Eight more bodies were retrieved today as rescuers successfully got access to the fourth floor near the bow", it said.

Earlier Saturday, the search had been suspended due to fast currents and high waves whipped up by gusty winds, according to a coastguard spokesman.

Dive teams have been working in challenging and sometimes hazardous conditions.

They have to grope their way down guiding ropes to the sunken ship, laying on its side on the seabed at a depth of 40 metres (132 feet).

They have to struggle through narrow passageways and rooms littered with floating debris in silty water.

Park Seung-Ki, spokesman for the Ministry of Oceans and Fisheries, said bedding materials from the ship were found as far as 30 kilometres (around 20 miles) from the disaster site on Friday.

As days go by, personal belongings and debris from the ship have been spotted further and further away, fuelling concerns that strong currents may have swept some bodies into the open sea.

One body was retrieved Friday by a fishing vessel four kilometres away from the recovery site, and another was found two kilometres away on Wednesday.

As a precaution, recovery workers put rings of netting around the site days ago.

The relatives of those still missing are insisting that all the bodies be recovered before efforts begin to raise the sunken ferry.

The Sewol capsized on April 16 with 476 people on board -- more than 300 of them from the same Danwon High School in Ansan city, just south of Seoul.

It is one of South Korea's worst peacetime disasters but public anger and frustration has been amplified due to greed and irresponsibility being blamed for the poor handling of the catastrophe.

The captain and 14 of his crew have been arrested for being the first to leave the ship without helping all passengers to safety.

The Sewol's regular captain, who was off duty on the day of the accident, has told prosecutors that the ferry operator -- Chonghaejin Marine Co -- "brushed aside" repeated warnings that the 20-year-old ship had stability issues following a renovation in 2012.

Two Chonghaejin officials were arrested on Friday on charges of having the ferry overloaded well beyond its legal limit.

The ferry owners have also become the focus of an ever-widening probe.

The government has come under strong criticism over the initially slow rescue response as well as lax safety standards and collusion between industry and regulators, which were partly blamed for the scale of the disaster.