Volunteering England has asked charities and volunteer-involving groups to submit evidence to its inquiry on volunteer rights.
The inquiry, which was launched last month, will produce a report that explains the rights volunteers have and the ways in which these should be upheld in practice.
It will also cover different models of redress that can be used to resolve disputes.
Volunteering England is asking for information about cases in which volunteers have complained that they were being unfairly treated and for ideas about how disputes involving volunteers should be resolved.
It will host evidence-gathering sessions in York, London and Birmingham in January and February at which volunteer-involving groups will be able to raise concerns.
Sukhvinder Kaur-Stubbs, chair of the inquiry panel, said: "Volunteers do have certain rights and protection under existing law. However, the over-riding concern was that volunteers did not demand equal employment rights but parity of esteem. This is as much about being treated with dignity, respect and fairness as it is about proper management and good governance."