Prominent Kenyan human rights activist Boniface Mwangi has been released without charge after being detained by police on suspicion of inciting violence, his wife told the BBC.

She described on Sunday how six masked individuals forcibly took him from his home.

His detention came after he called for an anti-government protest at a marathon in the capital, Nairobi, on Sunday. The police had confirmed that Mr Mwangi was in custody but did not provide further details.

His detention caused outrage among his supporters, who demanded his release.

He had been rallying people on X (formerly Twitter) to demand the resignation of President William Ruto, using the hashtags #RutoMustGo and #OccupyStanChart, which referred to the Standard Chartered marathon, the official name of the race.

He urged people to dress up in the colours of the national flag, wear bandanas with the message "RutoMustGo" and share protest chants online.

"Stay calm and peaceful and have fun!" he added.

Mr Mwangi has been arrested and released on numerous occasions over his campaigning.

His latest call for a protest was seen as an attempt to keep up pressure on Mr Ruto, who has faced growing public anger over the escalating cost of living and alleged police brutality during demonstrations earlier this year.

The activist's wife, Njeri Mwangi, told the BBC on Sunday that he was arrested at dawn that day at his home in Machakos County, about 40km (25 miles) east of Nairobi.

A group of five masked men and one masked woman, all in plain clothes, roughed up her husband before taking him away, she said.

"They allowed him at least to dress up and then they walked him out," Mrs Mwangi told the BBC.

Hours later, police confirmed that Mr Mwangi was in custody at a police station in downtown Nairobi.

Mr Mwangi’s lawyer condemned the detention as an abuse of power.

Ruto was elected president in 2022 after he pledged to champion the interests of what he called the "Hustler Nation", a reference to poor and unemployed people, especially the youth.

But he faced mass protests in June and July after he announced plans to increase taxes.

He dropped the plans, and brought the main opposition party into the government in an attempt to quell public anger.

Kenya's parliament also impeached his deputy Rigathi Gachagua more than a week ago with the apparent backing of Ruto.

Gachagua was accused of a raft of crimes - including fuelling ethnic divisions and violating his oath office.

He denied the charges, and described his impeachment as a "political lynching".

Ruto says he is committed to governing in the interest of all Kenyans, and ensuring that the economy improves.