A "culture of denial" over sectarianism exists in some areas of Scottish life, according to an academic who headed up a review of the issue.

Duncan Morrow led the Scottish Government's Advisory Group on Tackling Sectarianism, which reported its findings in May 2015.

The group had made several recommendations including an "urgent" requirement for football clubs to be punished for sectarian behaviour of their fans, known as strict liability.

On Monday, Mr Morrow published his review of progress made against the proposals 18 months on.

He said he believes sectarianism remains a "deep-rooted and serious problem which continues to manifest itself in areas across Scottish society".

Mr Morrow said there is evidence a "culture of denial exists in some areas and this culture remains an obstacle to progress."

In his update, the Ulster University academic stated "sectarianism remains an issue which causes discomfort and a degree of uncertainty among people in authority."

During the review, Mr Morrow obtained responses from a range of participants in the original work, including various church organisations, the Scottish FA, Police Scotland, the Grand Orange Lodge of Scotland and several councils.

He found while none of the respondents "denied the existence of residual sectarianism in general" he stated the presence of it in any specific organisation or group was "energetically refuted".

Mr Morrow said: "Attempts to name sectarianism, for example in flute bands, football, education, journalism or political and cultural life, are more often than not met with energetic denial and a sense that the remedy will be destructive of associations and passions which are regarded as positive."

He added: "The demand for 'evidence' [of sectarianism] too often appears to be a mechanism for defensiveness and minimisation rather than an interested inquiry for further information."

The Scottish Government has been urged by the academic to prioritise ending the "the behaviours, attitudes and structures that underpin sectarianism rather than 'name and shame' any individual or group."

He also recommended: "The maintenance and development of a quantitative and qualitative evidence base will be critical to ensuring action to prevent both denial and unevidenced prejudice and to illustrate progress and achievement."

In response to his update, community safety minister Annabelle Ewing said "work remains to be done in eradicating sectarianism from sections of our society".

She added: "Considerable work has been taken forward over the past few years and I am very pleased to note that some progress has been made since the final report by the Advisory Group but more needs to be done.

"The Scottish Government cannot eradicate sectarianism in isolation and while we are committed to taking forward the recommendations that are for us, we must also continue to work with local authorities, the third sector, community groups, football clubs and more to foster a Scotland where sectarianism is consigned to history.

"Together we can nurture a modern nation that isn't weighed down by the prejudices of the past."

The Scottish FA and SPFL issued a joint statement which read: "This season both the Scottish FA and SPFL have updated and tightened rules and guidelines on unacceptable conduct to help ensure our stadiums are safe and friendly environments where all fans can enjoy their football.

"We will monitor the success of those changes and we continue to work with the Scottish Government on further actions and future improvements in this area."